In the second one, I followed the steps shown here : http://forum.ubuntu-gr.org/viewtopic.php?f=9&t=3400Through Alt+F2, I extracted the files of xampp in the /opt , the directory for xampp is : /opt/lampp/htdocs/xamppWhen I type localhost in firefox, I get this message :

It works!This is the default web page for this server.The web server software is running but no content has been added, yet.

,however no page for configuration of xampp opened.Also, the index.php file found in the htdocs directory says :

I deleted the lamp file from /opt and tried it all over again. The same result.Also, when I type /opt/lampp/htdocs/xampp start in terminal, i get a message that it did not find the directory the directory is there!Help! I use linux 10.04.1

Another odd thing, is that when I tried to change the permission of the htdocs - as seen in the second guide - it does not let me change them.

A. - you won't be able start apache without root access. If you are getting an 'su authentication failure' - it means you either don't have/possess a valid 'root' password or the context you are in does not allow that. So you need to fix that first.

B. - The other issues are a consequence of that problem. Including why you can't 'chown' the files.

C. - tuxer is right - its /opt/lampp/lampp start - BUT you can only do that in superuser mode.